I decided to make the Fraction Calculator developed in Chapter 21 of the text available from the App Store. It is available at no charge. There are several enhancements, including a better UI design (see attached pic). The complete XCode project is available for download from this URL.

Note that the zip contains the app with the bug fix (as noted later in this thread).

EDIT *******You may disregard the request below. The next book I am reading (Cocoa Programming for Mac OS X - Hillegass) looks like it might teach me what I need to know.

Thanks again for a great book and a very helpfull web site.********************************************

Hey Stephen,These forums have been very helpful to me as I've been working my way through your book.

I just completed the calculator project and think it's very cool. In fact, I'd like to make the same calculator for use on the Mac.

I've tried to do this on my own, but I've run into some issues. When choosing the template for the project, I selected Application on the left and Cocoa Aplication on the right. The problem I'm having is that I didn't have a xxxxViewContrller.h file and don't know what would take it's place in this application.

Could you please provide a rough outline of the steps that would be required?

I downloaded the source of the Fraction Calculator and compiled it on the iPhone Simulator and came across a problem. Whenever you type in 3/2 ÷ 3/2 and then click plus, it says the answer is 3 when the answer is 1. I searched back through it and found out what the problem is. The processOp method looks like this:

If you can't see what I changed, I rearranged the top part of the method to include a "char oldOp" and set that to "op" before where you set "op to equal theOp", and the down below where the "if (firstOperand == NO)" statement, I changed the op to perform "oldOp" instead of "op" because the problem was that it was adding instead of dividing. You need to change that and then resubmit it to the app store.